Turn off unused lights
Turn lights off whenever you leave a room. Two 100-watt incandescent bulbs switched off an extra two hours per day could save you $15 over a year. Better yet, switch to LED.
Use timers or smart home technology
Set it and forget it. A timer will ensure your indoor lights go on only from dusk until bedtime, making your home look occupied and safe without wasting energy unnecessarily. Smart home systems enable you to control lights remotely when you are not at home.
Maximize natural light
A single south-facing window can illuminate 20 to 100 times its area. Keep the curtains open rather than turning on a light during daylight hours.